Hello Brad,
I have just found this website and came across this thread. How did your search progress as I have the exact same problem.
Richard Downing is also my GGGGG Grandfather and have James and Mary being his parents but cannot locate a marriage between the two so have no idea what Marys maiden name was. Did you manage to resolve this?
I have
Richard & Susanna James, Richards parents - James & Mary ? , James parents -Robert & Elizabeth Gosnal, Roberts parents, Robert & Grace Edwards/Rowe, Roberts parents Richard(e)and Philipa Phisick, Roberts parents etc etc, but this all relies on 'Mary' being the right person.
Can you assist or confirm to the best of your knowledge that I am indeed on the right track?
Many thanks
Joanna Downing